WO 2013/152374 A2 discloses a power factor correction circuit comprising a converter with a switch for in response to a control signal controlling an amplitude of an output signal and with a control loop for in response to a detection of the amplitude of the output signal producing the control signal. Thereto, the control loop comprises a circuit that receives a precise analog value or a precise digital value of the amplitude of the output signal and in response produces the control signal.